For the application to a Non-Imm-Visa Class (based on retirement, married to a Thai wife, sponsoring half Thai child, employment, etc.) outside of Thailand, you prove money in your home bank account or your monthly income, using original income documents.
For example, if you wish to apply to the Non-Imm-O Retirement Visa, you need proof of a deposit in your country’s currency equivalent to 800,000 THB – in ANY bank account ANYWHERE as long as it is in your sole name. Or a proof of a monthly income minimum of 65,000 THB equivalent.
Only when applying on Immigration inside Thailand, for a 1-year Extension of Temporary Stay Permit based on Retirement, the 800,000 THB deposit must be in a THAI bank account in your sole name.
So, right after you have entered Thailand on a Non-Imm Retirement Visa, you should get a Thai bank account opened as soon as possible, because you will need to season the deposit for 2 months before you can apply for the 1-year extension.
Thai bank account opening MINIMUM pre-requisites are:
*** have a longterm visa, like a 90-days Non-Imm-visa type, an LTR or Non-O/A
*** be properly registered per TM30 Online System at your accommodation
*** visit Immigration and get the “certificate of residence”. Immigration in this document will ask the bank explicitly to open a bank account for the applicant
*** have a Thai mobile number and the SIM-card registered to your name and passport number
*** your passport as a valid document of identification
(some banks have started to ask you for another piece of identification, like your home country driver’s license)
*** a work permit (only if applicable – it is NOT a mandatory requirement!)
Here a list of NOT commonly NECESSARY pre-requisites, but which CAN get asked from (incompetent!!) bank staff:
*** a rental contract - actually irrelevant- but it is okay if you got one, or if you got a blue housebook indicating ownership of a condo.
*** a third piece of identification (check above)
*** a mandatory life-insurance or accident insurance the bank offers you for yearly 5000 Baht (they love to earn a sidekick)
*** your foreign Tax-number or Social Security number (which would be okay so far, why not)
Try several branches of different banks, you might find one that opens an account for you under the minimal requirements. Sometimes it takes a day or two of running around until you find a bank willing to help you.
I don’t recommend Bangkok Bank. Better get a Kasikorn or Siam Commercial Bank Plc. Account. Other good banks are Khrungthai and Khrungsri
In case you consistently meet bank staff who resist and pull out of their noses random requirements, use the service of an agent. In Pattaya for example, you can get your Thai bank account opened for 5000 THB.